This page of The Elder Scrolls Online guide has information on how to manage multiple characters. You'll find out, e.g. how many characters you can create in TESO, how to unlock more character slots, as well as how to delete a character and what are the consequences.
When you start the game for the first time, you will be greeted by the character creator. After restarting the game (or after logging out of the first session), the main menu will have a Select Character option.
The default number of characters is eight - you have complete freedom in creating them. You can have, for example, a few characters of the same race, alliance, or class.
If you want to change the character, press Log Out in the options to return to the main menu.
You can delete characters in TESO - select a character and press the right button. However, there are some extremely important things to know:
- Once the character is deleted, you cannot get it back. Having a backup save won't help here either. Since TESO is an MMO, you can't manage your save files.
- The number of possible deletions is limited.
- Once a character is deleted, you will lose all the items it had in the inventory.
- If you want to keep any of the items that were used by your character, you must visit any bank in the game world and deposit them. This is particularly important for items purchased with microtransactions - the Crown Store uses real money. Remember to deposit these items in a bank, otherwise you will waste the money spent on buying them.
- The game doesn't delete mounts, pets, outfits, and upgrades. They are permanently assigned to your TESO account, not to individual characters.
To confirm your decision, you must press all the buttons shown on the screen. Only then will the character be deleted.
If the default number of character slots is not enough for you, you can buy more slots. Go the Upgrades tab in the Crown Store.
The Additional Character Slot costs 1,500 Crowns - it adds 1 new character slot. You can purchase a maximum of 10 slots, meaning you can have up to 18 characters.